Tagging Summary

All Data Excludes TGM

Throughout the study, there have been a total of 18821 fish tagged with PIT tags. Of these fish, 6915 were trout or sculpin tagged within the study area. 11900 fish were Tiger Muskies tagged and released in Shadow Mountain Reservoir, and 6 tags were mergansers tagged as part of an avian predation study. There have been 762 instances of fish recapture throughout the study period. The table below breaks down release and recapture data by year and species on tags other than Tiger Muskies.

The following interactive plot shows the length distribution of tagged fish (besides Tiger Muskies) by year, length and species. The proceeding table shows summary statistics of released species’ lengths and weights by year.

There have been a total of 27 sites where tagged fish have been released and 24 sites where fish have been recaptured over the course of the study. The following tables show yearly counts of released and recaptured fish by site and species.

Movement Summary

Fish detected by antennas, released, or recaptured are assigned a one letter “State”, defined as a specific section of the river outlined in the map below. The following tables summarize activity in the Connectivity Channel (CRCC) as defined by movement between the “States” upstream of the channel, downstream of the channel, and within the channel throughout a fish’s encounter history. Antenna locations can be toggled with the layer control.

Upstream or downstream movements of fish occur when a fish is detected or recaptured in a different area than before, even if a fish remained in the same state. By monitoring these movements over time, we can start to see patterns about when fish activity is highest. “No Movement” is defined when a fish hits the same antenna as before on a different day. The following graph and table show an overall increase in activity in the Spring and Fall, when spawning occurs in rainbow trout and brown trout and water temperatures change.

The following graph and table shows total movements by fish size.

Antenna data

When a tagged fish swims across an antenna, it registers a detection on that antenna. When the fish remains on an antenna, it registers detections until the fish swims out of the detection field. The following graph and table show the raw amount of detections per antenna across the entirety of the study.

Sometimes these antennas lose power for a certain period of time. Stationary Antennas were down for 3.51% of the total time across all Stationary Antennas. All individual Stationary antennas were down for a total of 572.83 days out of a total of 16313.71 days of total time across all Stationary antennas. Biomark antennas were down for 2.06% of the total time across all Biomark antennas. All individual Biomark antennas were down for a total of 31.35 days out of a total of 1525.72 days of total time across all Biomark Antennas.

Stationary antennas detected 1256 fish that were not detected by mobile, biomark, or recapture methods. Biomark antennas detected 146 fish that were not detected by mobile, stationary, or recapture methods. Mobile antennas detected 1143 fish that were not detected by biomark, stationary, or recapture methods. There were 185 fish recaptured that were not detected by biomark, stationary, or recapture methods.

Before and After CRCC Construction

Before the Connectivity Channel was built, there were 29 upstream journeys from Hitching Post Antenna or Windy Gap Biomark Antenna (both located downstream of Windy Gap dam) to Confluence Antenna (located upstream of Windy Gap dam) by non-Avian Predated fish and 36 downstream journeys from Confluence Antenna to Hitching Post Antenna or Windy Gap Biomark Antenna, over the course of 1167.14 days. This equates to one upstream journey every 40.25 days and one downstream journey every 21.56 days. Since the Connectivity Channel was built, there have been 77 upstream journeys from Hitching Post Antenna or Windy Gap Biomark Antenna to Confluence Antenna by non-Avian Predated fish AFTER Channel was built and 90 downstream journeys from Confluence Antenna to Hitching Post Antenna or Windy Gap Biomark Antenna below the dam, over the course of 776 days. This equates to one upstream journey every 10.08 days and one downstream journey every 8.62 days on average.

In comparison, before the Connectivity Channel was built, there were 275 upstream journeys from Red Barn Antenna to Hitching Post Antenna by non-Avian predated fish and 362 downstream journeys from Hitching Post Antenna to Red Barn over the course of 1167.14 days. This equates to one upstream journey every 4.24 days and one downstream journey every 3.22 days. Since the Connectivity Channel was built, there have been 160 upstream journeys from Red Barn Antenna to Hitching Post Antenna by non-Avian predated fish and 254 downstream journeys from Hitching Post Antenna to Red Barn over the course of 776 days. This equates to one upstream journey every 4.85 days and one downstream journey every 4.6 days on average.

Avian Predation

Throughout the duration of the study, we have identified 59 fish that have been predated by birds. These tags are found a few different ways:

Below is the encounter history of a Merganser tagged in 2024. Activity is excessive between Red Barn and Hitching Post and later do not follow a typical fish sequence when travelling upstream. The Merganser was detected on the Hitching Post antenna below the dam, then was detected on an antenna above the dam without hitting other antennas between, as shown in the animation below. The Merganser also is typically detected briefly on an antenna before travelling off of it. By recognizing movements patterns of known birds, we can apply this pattern to finding tags predated by birds.

In contrast, below is the encounter history of a 335 mm Brown Trout. Antennas hit follow a logical sequence for fish and there more time between detections at different antenna sites. In contrast to the merganser, the fish lingers on antennas as opposed to only a brief detection at antennas. The fish moves more in the fall, when you’d expect a brown trout to move for the spawn. The fish moves around a lot, but follows a logical sequence of antennas, as shown in the animation below for the selected time frame, when the fish moves upstream through the channel before moving back down and up, hitting all antennas along the way.